Expansible mandrel or chuck.



1 "110,714,44 Patented Nov. 25, I902.

J. H. BRYAN. 'EXPANSIBLE MANDREL 0R CHUCK.

(Application filed July 2, 19021 (No llodal.)

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UNITED STATES PATENT @FFICE- JOHN -H. BRYAN, OF BALTIMORE, MARYLAND.

EXPANSIBLE MANDREL OR CHUCK.

SPECIFICATION forming part of Letters Patent N 0. 714,448, datedNovember 25, 1902.

' Application filed July 2, 1902. Serial Nd. 114,108. (No model.) i

To all whom it may concern: i Be it known that 1, JOHN H. BRYAN, acitizen of the United States, residing at Baltimore, State of Maryland,have invented certain new and useful Improvements in ExpansibleMandrelsor Chucks, of which the following is a specification. V

This invention relates to improvements in expansible chucks or mandrelsdesigned for attachment to a milling-machine or lathe for the purpose ofholding articles that are to be bored, faced, or turned.

One of the objects oft-he invention is to pro? vide an improved deviceof this character that maybe tightly clamped within the article to beworked upon without danger of scoring, warping, or otherwise injuringthe interior of the article; and a further object of the inventionis to provide such a device with a shank which while primarily intendedto spread apart the clamping-jaws may also be used in place of alive-center in conjunction with the usual dead-center, in which case thedeadcenter will assist in rigidly supporting the chuck against lateralstrain. 5 With these and other objects in view the invention consists ofcertain constructions and combinations of parts hereinafter fullydescribed and claimed, reference being had to the accompanying drawings,in which- Figure 1 is a side elevation of myimproved expansible chuckshown as applied to the spindle of alathe in j uxtaposition to thedeadcenter of the same. Fig. 2 is a longitudinal sectional view of thechuck on a larger scale and with parts in side elevation. Fig. 8 is anend View. Fig. 4 is a detail view illustrating a modification.

Referring to the drawings, Fig. 1, the letter ct designates the tubularrotary spindle of a lathe, which spindle is ordinarily adapted toreceive a rod with a hardened point, called the live-center, andintended to coact with a similar hardened point I) on a rodb, called thedead-center. As is well known, the said spindle forms partof thehead-stock of the lathe, and the dead-center b is secured in thetail-stock, which is adjustable longitudi-. nally toward and from thehead-stock in the usual manner.

My invention is intended to be used for holding hollow work, such aspiston-rings and mentioned, and it comprises a shank A, provided with atapering end 0, adapted to fit within the spindle a, as illustrated inFig. 1, said shank being threaded, as at d, and provided with jam-nuts(1, whereby to prevent the insertion of the shank within the spindlefarther than the desired position. At a point between its ends the saidshank Ais provided with a circumferential flange c, and at its endopposite the tapered end 0 the said shank is sharply beveled, as at f,said bevel merging into a cylindrical nose g, which is provided on itsouter face witha small socket g, as illustrated in Fig. 3.

A hand-wheel B is provided with a cylindrical hub 7t, surrounding saidshank A and having an inwardly-extending flange h, taking over thecircumferential flange e and bearing on the shank, and said hub isinternally screw-threaded, as shown at 72. and receives within it theexternally-threaded endz' of a cylindrical jaw-casing C. A featherscrcwjextends through said casing end into a longitudinal groove It in theshank, whereby the revolution of 'the hand-wheel B will effect alongitudinal movement of the jaw-casing with respect to the shankwithoutanyrotary movement of said casing. The said jawcasing O isprovided with a butt-flange Z and a polygonal head 1%, in each of Whosesides is formed a radially-extending aperture 42 and in whose outer face0 is formed a central aperture p, as illustrated in Figs. 2 and 3, thelast-named aperture receiving the nose 9 of the shank A for a purposepresently described.

In each of the radial aperturesn is moun ted the stem q of aclamping-jaw, whose head r is sector shape in section, with its convexside outermost, and the said convex sides together form an approximatelycircular expansible part of the chuck to bear outwardly against anarticle inserted thereon. Each of the stems q is beveled at its innerendq to ride on the beveled end fot the shankA and is provided with alongitudinal groove g in which fits a feather-screw s. The inner ends ofthe jaw-heads r are in sliding contact with one wall of the butt-flangeZ, as illustrated in Figs. 1 and 2. h

In order to clamp a piston-ring or similar article inserted over thecircle of clampingsimilar articles, in place of the live-center just ijaws, the hand-wheel B is turned so as to draw the jaw-casing O inwardlyon the shank A, which action causes the beveled stems q to ride up onthe beveled endfof the shank, thereby moving the jaws outwardly intoclamping engagement with the article. The butt-flange Z serves as an endstop for the article.

If desired, the dead-center b may be moved up, as indicated in dottedlines, Fig. 1, and the nose 9 projected out through the aperture 19 inthe outer face of the jaw-casing, so that the point Z) of thedead-center may enter the socket g in the said nose to assist insupportin; the chuck for very heavy work.

The shank of the chuck may be constructed as illustrated in Fig. 4, inWhich the said shank designated A is similar to the beforedescribedshank A, with the exception thatit is provided on one end with acoupling-sleeve 2f, adapted to screw over the lathe-spindle c.

Having thus described my invention, What I claim as new, and desire tosecure by Letters Patent, is-

1. An expansible mandrel or chuck, comprising a shank adapted forattachment to the spindle of a lathe or the like and provided with abeveled end and with a circumferential flange between its ends; ajaw-casing movable longitudinally on said shank; clam ping-jaws carriedby said casing and adapted to ride on the beveled end of said shank; anda wheel mounted on said shank and provided with an in ardly-extendingflange taking over the circumferential flange of the shank and alsoprovided with a screw-thread ed engagement with said jaw-casing, as setforth.

2. An expansible mandrel or chuck, comprising a shank provided with abeveled end and a circumferential flange intermediate its ends; ahand-wheel provided with an inwardly-extending flange taking over saidcircumferential flange and also provided with an interiorly -threadedhub; a jaw-casing movable longitudinally on said shank and provided withan exteriorly-threaded end entering and engaging with said hub and saidcasing also provided with a buttflange, Z, and a head havingradially-extending apertures; and clamping jaws having stems mounted insaid apertures and adapted to ride on the beveled end of said shank, asset forth.

3. An expansible mandrel or chuck, comprising a shank provided with abeveled end and a cylindrical nose, 9, projecting beyond said end; ajaw-casing movable only in a 10ngitudinal direction on said shank andprovided with radially-extending apertures, '21 andan outer face, 0, inwhich is formed a central aperture, 19, through which latter the saidcylindrical nose may project; and clamping-jaws provided with stemsmounted in said radially-extending apertures and adapted to ride on thebeveled end of said shank, as set forth.

4. An expansible mandrel or chuck, comprising a shank provided with abeveled end and a nose projecting beyond said end; a

jaw-casing movable longitudinally on said shank and provided with apolygonal head having an aperture in each of its sides and a centralaperture in its outer face which latter aperture is adapted to receivethe said nose; and a clamping-jaw mounted in each of said sideapertures, and adapted to ride on the beveled end of said shank, as setforth.

In testimony whereof I affix my signature in the presence of twoWitnesses.

JOHN H. BRYAN.

Witnesses:

CHARLES L. VIETsoH, FREDERICK S. STITT.

